Is a turn considered "taken" at its start or the end? (re: Assassinate and new bugbear PC features)

Question

Looking at the rules for the 5e Assassin subclass (and similarly for the PC Bugbear Surprise Attack feature),

Assassinate

Starting at 3rd level, you are at your deadliest when you get the drop on your enemies. You have advantage on attack rolls against any creature that hasn’t taken a turn in the combat yet. In addition, any hit you score against a creature that is surprised is a critical hit.

and similarly for the Bugbear race from Mordenkainen Presents,

Surprise Attack

If you hit a creature with an attack roll, the creature takes an extra 2d6 damage if it hasn’t taken a turn yet in the current combat.

I wasn't sure whether an attack made as a reaction during the creature's turn would still receive advantage from this feature. My instinct is that a turn is considered "taken" at its end, and this part from the PHB

The Order of Combat

A typical combat encounter is a clash between two sides, a flurry of weapon swings, feints, parries, footwork, and spellcasting. The game organizes the chaos of combat into a cycle of rounds and turns. A round represents about 6 seconds in the game world. During a round, each participant in a battle takes a turn. The order of turns is determined at the beginning of a combat encounter, when everyone rolls initiative. Once everyone has taken a turn, the fight continues to the next round if neither side has defeated the other.

seems to indicate that this is the case, since that last character's turn has to be completed in order for combat to continue after it has taken its turn.

The hypothetical I'm thinking of is a Bugbear Assassin rogue with 2 levels in fighter that gets the drop on the enemy, surprising the creature, and the rogue goes first, with the creature taking its turn immediately after the rogue. The rogue attacks and gets all the extra damage features etc., then uses Action Surge to take the Ready action.

The rogue readies an Attack action with the trigger being the start (or middle) of the creature's turn, with the intention of benefiting from Sneak Attack a second time this round by attacking with a Reaction after the rogue's turn has ended. The creature should still be under the effect of surprise (as it cannot take actions until the end of that turn), but would the Surprise Attack feat and advantage part of the Assassinate feat still be active after the creature's turn has started (but not ended)?

I imagine the trigger could be rephrased to, "just before the creature takes its turn," to resolve ambiguity, but it seems like we run into trouble in getting that second Sneak Attack damage if the creature goes immediately after the rogue–this is in contrast to the rogue taking their turn, some third creature taking its turn, and then the creature in question taking its turn. As near as I can tell, there is no "in between" time in combat from one turn to the next, meaning in this situation either the creature has started its turn or the rogue has not ended their turn.

So, in the situation of rogue then creature goes, would this readied Attack benefit from the advantage in Assassinate and the bugbear's Surprise attack damage? Again, the common sense answer feels like yes, but I want to know if that's how it would be adjudicated vis-à-vis RAW.

Answer 1

You cannot ready an action in response to a 'turn'

I agree with Dale M that linguistically a creature may have 'started taking' its turn, but it has not taken its turn until the turn's conclusion.

More importantly, however, you have no justifiable trigger for your readied action. You can only ready your action for a 'perceivable circumstance'. You want the trigger to be "the start (or middle) of the creature's turn," but this is not something that your character, in-game, can perceive.

Initiative order and game turns are abstractions to facilitate combat, not something that the characters perceive (and see: Can you ready an action for "immediately before my next turn"?).

Now, your bugbear rogue / fighter could certainly ready an action in response to the target moving, or drawing its sword, or somesuch action that would normally indicate that its turn had started. However, in the specific scenario you posit of the target being surprised, it cannot take actions during its first turn - so you have no perceivable circumstance to ready your attack for.

A surprised creature can't take a reaction until after its first turn in the combat ends. Thus, at some point in the combat round, it goes from a state of not being able to react to being able to react. That could be considered a 'perceivable circumstance' and at my table I would allow someone with a high Passive Insight to ready an action to attack when the target 'is no longer surprised' or 'when they realize they are under attack'. In your particular case this still does not help, though, because this change happens at the end of their turn and so you cannot use your 'before they have taken their turn' bonuses.

Basically your dilemma is that you want them to do something you can react to, but you also want them to be surprised, and if they are surprised they cannot do anything that you can react to.

But maybe you know a bard

Rather than taking an expensive two-level dip in Fighter just to give your Bugbear Assassin an Action Surge it can use only once per rest, it is likely more efficient and reproducible to have someone on your team that can cast fear, dissonant whispers, or another spell that forces your target to leave your reach using their own movement. If that caster can take their turn before your target and force them to flee, you can then use your own reaction to make your second attack, an opportunity attack, before your target has finished taking their turn, with all the extra damage that implies.

Note that in order for this to work (and thanks @Morgan for making this explicit), the target can't be surprised, since they will need an action or reaction available in order to move. Thus it will work any time the target is not surprised, but both you and your bard ally have a better initiative than the target. Such a situation means that you don't get to use your Assassinate for an automatic critical, but you still get the Assassinate for advantage, triggering your Sneak Attack, and you still get your Bugbear Surprise Attack extra damage (which doesn't require that the target be surprised, because of course it doesn't). This does do less damage than you had hoped for, but it is much more reproduceable because it can potentially be used every combat (rather than once per rest). Furthermore, depending on how your DM adjudicates surprise, it is likely that combats in which both you and your bard ally have a better initiative than at least one of your opponents will be far more common than combats in which you have surprise against any of them.

You did express reservations about involving a third person in the situation because the combat round is simultaneous, but you needn't worry about that. While it is true that narratively your Assassin, their target, and their bard ally are all acting simultaneously, within combat we use Initiative as an abstract construct to resolve effects in turn order, so there are no problems with saying that the assassin attacks on their turn, then the bard casts dissonant whispers on their own turn, and then your target runs on their own turn permitting you to react by making an opportunity attack before the end of the target's turn.

Answer 2

It seems to be against the spirit of the ability, but ask your DM

Linguistically, you only have “taken a turn” when it's over.

However, both abilities are related to surprise and ambushes. In this context you are looking at the first round of battle, when opponents can be surprised.

On that round, the bugbear or assassin can go before or after an opponent in the initiative order. If they go before, whether they surprised the opponent or not, they clearly “got the drop” on their opponents, and get advantage or extra damage. If they instead come after an unsurprised opponent in initiative, they did not “get the drop” on them. The opponent is already actively acting.

I think “taking a turn” can either be read as starting the turn or as taking the entire turn, depending on context. And in this context, the situation would indicate it is about who gets the drop on whom, who already is acting, not about who has already finished their turn.

I therefore think it is the DM's right if they want to read this as you suggest and allow the Ready action shenanigans that you describe, or to say “nice try” but rule that you only get advantage or extra damage as long as the opponent has not started their turn.

Another issue in your scenario is that Initiative order is purely a construct for resolving play. In the game world, all participants are acting during the same six seconds in the round, they do not know anything about round or turns. Because a character can only use a perceivable circumstance as the trigger for their Ready action, you cannot declare a trigger for a Reaction that is based on a creature starting its turn. You need to pick something the character can observe the opponent doing, like moving or attacking.

Answer 3

Taken is the past participle of the verb take

The present participle is taking.

So, your reading is correct, a creature has not “taken” their turn while they are still “taking” it.